Viscosity gauging device

ABSTRACT

A viscosity gauging device wherein two weighted pistons which are kept raised by crankcase oil pressure drop when the pressure is cut off. The pistons travel the same distance when the viscosity of the crankcase oil matches the viscosity of a standard sample, but relatively different distances when the crankcase oil is thicker or thinner than the sample. A flexible wire contact is located beneath each piston and arranged so that no circuit is closed if both pistons move to the same extend, but a circuit is closed if either one moves further than the other. The closing of the circuit operates a remotely located signal to show that the crankcase oil needs attention.

United States Patent 3,l53,927 10/1964 Gerin ABSTRACT: A viscosity gauging device wherein two weighted pistons which are kept raised by crankcase oil pressure drop when the pressure is cut off. The pistons travel the same distance when the viscosity of the crankcase oil matches the viscosity of a standard sample, but relatively different distances when the crankcase oil is thicker or thinner than the sample. A flexible wire contact is located beneath each piston and arranged so that no circuit is closed if both pistons move to the same extend, but a circuit is closed if either one moves further than the other. The closing of the circuit operates a remotely located signal to show that the crankcase oil needs attention.

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l 3 2 h It 31 4 7 1 8 PATENTED JUN] 5 I97:

INVENTOR. Fernand L. Gerin.

Attorneys.

VISCOSITY GAUGING DEVICE This invention-is for an improvement in a crankcase oil condition indicator or other viscosity gauging device of the type shown in my US. Pat. No. 3,l53,927,granted Oct. 27, 1964.

In my patent above enumerated there is shown a viscosity gauging device particularly, but not exclusively, useful for warning an operator of a diesel engine when the crankcase oil needs attention. There is a easing into the lower end of which crankcase oil from the engine continuously. circulates while the engine is running, or unless the flow of oil is purposely stopped at intervals for an oihcheck. The pressure of the oil so supplied raises and holds elevated two weighted pistons. If the crankcase pressure fails, as when the engine isstopped, both pistons drop by gravity, butanisolated sampleof new fresh oil in a sealed compartment controls the downward movement of one piston while crankcase oil which flows. into a. second closed; compartment when the engine is operating and retainedwhen the-engine is stopped controlsthe dropping of the other piston. If the oils toboth weighted pistons are of about the same viscosity, bothpistons strike the opposite ends of a balance-lever at about the same time and their downward movement is stopped. The balance-lever is one rock shaft to which is attached a magnet that operates an indicator pointer, and when the indicator is in a central zone on an indicator scale, it shows this condition of balance. If the crankcase oil loses its viscosity, perhaps becoming diluted with fuel or some other liquid, its piston falls more rapidly than the other and strikes the balance-lever before the other one does, and drops further tilting the indicator to one side of the neutral zone to show a deficiency in the oil. If the crankcase oilbecomes emulsified with water or other foreign matter which increases itsviscosity and makes it flow slower, that piston which is controlled bythe isolated sample drops more rapidly, riding past the neutral stopping level, and the indicator is tilted in the opposite direction from the neutral zone. In either case, the crankcase oil requires attention.

While this instrument has provedto be quite satisfactory, the instrument itself must be close to the engine. In the case of a truck, the instrument is seen only if the driver stops'his truck and looks under the hood at the instrument. Likewise, in the case of a diesel engine operating at a remote distance from a control panel, as for example a pipeline pumping station, the instrument cannot be monitored at the control panel.

The present invention is for an improvement in which the instrument can operate a signal without visual inspection of the instrument at all. For example it may light-a light or lights on the truck panel, or in the case of a remote engine, transmit a signal to an attendant at a remote control panel or actuate an engine shutdown device.

This is accomplished by providing in the casing thin resilient contact elements in the path of downward movement of the pistons below the level where they can close a circuit when both pistons drop the same distance, but the one under the piston which lowers beyond the level of the other will complete a circuit to operate a remote signal.

In the accompanying drawingswhich illustrate a preferred embodiment of the invention and wherein corresponding reference numerals designate correspondingparts:

FIG. 1 is afront elevation to an instrument of the type of the casing is broken away to showthe parts with which this invention pertains.

There is a portion 3 at the bottom of thecasing having a nipple 4 to which a tube 5 leading from thepressure-lubricating:

system of the engine is connected. An opening. at 6 in the botoperating lever 8 provided for cutting off the flow of oil into the casing when it is desired to test the condition of the. oil with the enginerunning. This would be done bya mechanic or perhaps a truck driver who would be working'close to the engine where the instrument is located. Oil is returned from the instrument through an oil outlet nipple 9.

There are two metal cylinders 10 and 11 supportedon a transverse partition 12. One cylinder, as for example 10, opens at its top through a restricted orifice to a reservoir (not shown) in which is an isolated sample of unused crankcase oil that cannot become contaminated. The other cylinder 11 opens through a restricted orifice into a. compartment through which circulates the crankcase oil supplied through tube 5 from the engine, and conducted through a bypass valve (not shown) to a level above the tops of the cylinders.

Cylinder 10 has a metal piston 10A thatmoves up into the cylinder under the pressure of the oil supplied from the engine crankcase andconfines in the casing under the cylinders. Only the lowerportion of piston 10A, which is shown in the raised position in FIG. 1 can be seen, and the lower portion of the cylinder 10 is seen in section. There is a similar piston 11A in cylinder 11 that is also held in the raised position shown in FIG. 1 by the pressure of the crankcase oil in the lower part of the casing when the engine is running and crankcase oil is flowing through pipe 5 and port 6. Both pistons are of the same size and are solid or otherwise weighted to drop down when the oil pressure that supports them drops.

There is a balance-lever 15 under the two cylinders supported in the casing on a rock shaft 16,. with its opposite ends projecting into the path of travel of the respective pistons when they drop. The rock shaft is magnetically coupled to a pointer 17 outside the casing that moves under a protecting coverplate 18 in front of a scale near the top of the exterior casing. When the two pistons 10A and 11A drop onto thev balanced lever 15 so that both ends are at the same level, the indicator is at the midpoint on the dial. If one piston moves down in advance of the other, that is faster than the other, it will lower the end of the balance-lever which is beneath it, tilting the other end up, and the slower movingpiston is then stopped by contact with the raised end of the balance-lever, since it would be required to lift the faster moving piston to move down further and restore the balance-lever to a position where both pistons are at the same level. Stated anothcrway, the combined travel of the two pistons is always the same, but the distance that each piston separately moves depends on their relative rates of descent.

According to the present invention a contact is arranged under each piston at a level below the level of the balancelever whenit is at its level or neutral position, but positioned to be engaged by the piston under which it is positioned when that piston drops ahead of the other one. Each contact, how-- ever, is preferably sufficiently resilient to avoid interference with the downward travel of the piston under which it is positioned, so that the degree of extent of unbalance will still be accurately registered by the indicator 1'].

The contactstherefore each comprise an insulating block 20, one of which is-secured to each side of the casing. Each block hasa binding post carried thereby comprising a metal rod 21 passing through it and extending through an opening in the casing into thechamberunder the pistons, but out of contact with the casing. The outer end of each rod is threaded, and there is a clamping nut 22 on this threaded end that holds therod tight in the. bushing. There is a second nut 23 on the.

threaded end of each rod for holding the terminal of an electric wire on the rod. On the inner end of each rod there is a.

very fine resilient metal wire 24 that extends horizontallyinto the chamber under the pistons at a level slightly bclow the level of the ends of lever 15 when that lever is in its level posi- When either piston drops to a level below the other one to rock the lever to show an unbalance, the end of that piston will strike the free end of the wire 24 to close an electric circuit, but the wire will flex under the weight of the piston and offer no appreciable resistance to the continued descent of the piston, When the pistons are next lifted by oil pressure, these wires will spring back to their original position. The wires are eccentrically positioned on the ends of the rods 21 so that by rotating the rod 21 when clamping nut 22 is loosened, some slight vertical adjustment of the wire can be made. The wires 24 are in a plane at one side of the posts 108 and 118 on the respective pistons that keep them from dropping so far as to stretch or rupture the thin flexible sleeves that exclude the entrance of oil from the chamber below the pistons, which fit loosely in their cylinders, into the cylinders and which prevent the reverse flow of oil from above the partition 12 through the cylinders to the chamber below the pistons, all as more fully explained in my aforesaid patent.

In use, a wire 30 is attached to the outer end of one contactwire-supporting rod 21 and another wire 31 to the other one. These wires are connected at 32 to a wire 33 in which is a signal, such as a lamp or other visual and audible signal or both at 34. The other terminal of the signal 34 connects to a battery or power source 35, and the other side of the power source connects through a return circuit to the casing, which in the case of a vehicle is usually, as indicated, a ground. The casing itself is also grounded, as through oil inlet pipe 5.

Oil in an engine may become diluted with fuel, or its viscosity lowered in use. In this instance piston 11A will drop faster than piston 10A. The oil may increase in viscosity due to the formation of emulsions with water or other contaminant, in which case piston 10A would drop faster than piston 11A With this arrangement, if either piston descends more rapidly than the other, one of the contact wires 24 will make a circuit through the signaling device 34 to indicate that the oil needs attention, While the instrument itself is close to the engine, the signal device may be located on the vehicle dash or, in the case of pumping stations or like remote engines, at a location much further removed.

In addition to, or in lieu of signal 34, there may be separate signals 30a and 31a in lines 30 and 31 respectively, which would indicate whether the oil is too thick or too thin.

As hereinbefore indicated the device normally functions only when the engine stops and the engine oil pressure drops to let the pistons drop under the influence of gravity. If the operator of a motor vehicle wants to test the condition of the oil when the engine is running, or in the case of an engine located at a distance from a control panel where the engine is not frequently stopped, a valve, such as a solenoid-operated valve 40 with a solenoid 41 may be located in the oil supply line 5. By operating a switch 42 controlling this solenoid valve, which may be either a manual switch or a clock-operated switch that closes the solenoid circuit at regular intervals, the flow of crankcase oil to the instrument may be temporarily shut off to produce an actuation of the instrument the same as if the engine had been stopped.

While specific reference has been made to the use of the instrument for comparing crankcase oil of an engine with a particular sample of the same oil before use, it will be understood that the invention is applicable to various other applications where an instrument of this type is provided with two pistonlike elements, the relative movement of which is related to the viscosity of two liquids, that is, where the elements move together if the viscosity of two liquids to be compared is approximately the same, but more relative to each other where there is a difference in viscosity.

1 claim: 1. Apparatus of the type wherein the viscosity of a liquid relative to a selected sample is determined by the relative movement of two separate pistons which are moved in one direction by the pressure of the liquid being tested and both of which move in a reverse direction when the pressure of said liquid is dropped, and wherein one of said pistons moves in said reverse direction under the control of a sample a of the liquid'being tested and the other one moves in tin reverse direction under the control of the selected sample and both move the same distance in the reverse direction to the same common limit of travel when the viscosity of both liquids is about the same but one moves further than the other and past said common limit where there is a significant difference in the viscosity of the two liquids, and wherein:

a. the instrument has electric contact means therein arranged to respond only to a differential rate of travel of the pistons in said reverse direction to complete a circuit, said contact means being located in the path of move ment of the pistons and positioned to close the circuit only when one of the pistons moves past said common limit of travel for both pistons together and before a piston moving past said common limit has reached its full limit of travel, and

b. there is an external circuit connected to said contact means that comprises a signal and a source of power arranged to operate the signal when said circuit is completed through said contact means.

2. Apparatus for indicating an increase or decrease in the viscosity of the crankcase oil of an engine as compared with a standard sample of the type wherein there is a casing having an upper portion and a lower portion, with an oil inlet pipe for delivering oil to be tested into the lower position of the casing, provision being made for the flow of this oil from the lower portion of the casing into the upper portion of the casing, a pair of cylinders positioned between said upper and lower portions, a piston in each cylinder arranged to be moved upwardly by pressure of oil in said lower portion and to drop by gravity when the flow of oil under pressure to the lower portion of the casing is stopped, the rate of the drop of one piston being controlled by the crankcase oil in, the upper portion of the casing and the rate of dropping of the other piston being controlled by a selected sample of oil separate from the crankcase oil so arranged that both pistons drop at the same rate when the viscosity of the crankcase oil and the sample are approximately the same but when there is a significant difference in viscosity one piston drops faster than the other, a balance lever in the lower portion of the casing with one end in the path of movement of the other piston when it drops whereby said balance lever limits the downward travel of both pistons to a predetermined common lower limit when they drop at the same rate but one may move below said limit if it descends faster than the other and the slower one is stopped in its travel by said balance lever before it reaches said common lower limit, characterized by:

a. a contact under each piston in the path of downward travel thereof, said contacts being at a level below the ends of said balance lever when said lever is in level position and therefore below said common lower limit of travel of the pistons and so to be engaged by a piston only when a piston has moved below said common lower limit, and

b. an external circuit comprising said contacts, a signal and a source of power that is completed through the signal when one of said pistons engages one of said contacts.

3. Apparatus as defined in claim 2 wherein the signal is located at a remote distance from the casing and means is provided for stopping the flow of oil into the lower portion of the casing while the engine is running whereby the condition of the crankcase oil may be determined at selected times and an indication given at the remote location without stopping the engine.

4. Apparatus as defined in claim 2 wherein the contact under each piston is a resilient wire supported in the casing and insulated therefrom at a level to be contacted when the piston under which it is positioned moves below the axis of rotation of the balance lever and above the lowermost limit of travel of said piston, the wire being sufficiently resilient to flex under the weight of the piston and not appreciably retard the movement of the piston.

5. Apparatus as defined in claim 4 in which each wire is separately supported on a binding post passing through the ble about its axis, the wire being eccentrically mounted on the inner end of the binding post whereby its elevation with respect to the piston under which it is located may be adjusted by rotating the binding post. 

1. Apparatus of the type wherein the viscosity of a liquid relative to a selected sample is determined by the relative movement of two separate pistons which are moved in one direction by the pressure of the liquid being tested and both of which move in a reverse direction when the pressure of said liquid is dropped, and wherein one of said pistons moves in said reverse direction under the control of a sample of the liquid being tested and the other one moves in the reverse direction under the control of the selected sample and both move the same distance in the reverse direction to the same common limit of travel when the viscosity of both liquids is about the same but one moves further than the other and past said common limit where there is a significant difference in the viscosity of the two liquids, and wherein: a. the instrument has electric contact means therein arranged to respond only to a differential rate of travel of the pistons in said reverse direction to complete a circuit, said contact means being located in the path of movement of the pistons and positioned to close the circuit only when one of the pistons moves past said common limit of travel for both pistons together and before a piston moving past said common limit has reached its full limit of travel, and b. there is an external circuit connected to said contact means that comprises a signal and a source of power arranged to operate the signal when said circuit is completed through said contact means.
 2. Apparatus for indicating an increase or decrease in the viscosity of the crankcase oil of an engine as compared with a standard sample of the type wherein there is a casing having an upper portion and a lower portion, with an oil inlet pipe for delivering oil to be tested into the lower position of the casing, provision being made for the flow of this oil from the lower portion of the casing into the upper portion of the casing, a pair of cylinders positioned between said upper and lower portions, a piston in each cylinder arranged to be moved upwardly by pressure of oil in said lower portion and to drop by gravity when the flow of oil under pressure to the lower portion of the casing is stopped, the rate of the drop of one piston being controlled by the crankcase oil in the upper portion of the casing and the rate of dropping of the other piston being controlled by a selected sample of oil separate from the crankcase oil so arranged that both pistons drop at the same rate when the viscosity of the crankcase oil and the sample are approximately the same but when there is a significant difference in viscosity one piston drops faster than the other, a balance lever in the lower portion of the casing with one end in the path of movement of the other piston when it drops whereby said balance lever limits the downward travel of both pistons to a predetermined common lower limit when they drop at the same rate but one may move below said limit if it descends faster than the other and the slower one is stopped in its travel by said balance lever before it reaches said common lower limit, characterized by: a. a contact under each piston in the path of downward travel thereof, said contacts being at a level below the ends of said balance lever when said lever is in level position and therefore below said common lower limit of travel of the pistons and so to be engaged by a piston only when a piston has moved below said common lower limit, and b. an external circuit comprising said contacts, a signal and a source of power that is completed through the signal when one of said pistons engages one of said contacts.
 3. Apparatus as defined in claim 2 wherein the signal is located at a remote distance from the casing and means is provided for stopping the flow of oil into the lower portion of the casing while the engine is running whereby the condition of the crankcase oil may be determined at selected times and an indication given at the remote location without stopping the engine.
 4. Apparatus as defined in claim 2 wherein the contact under each piston is a resilient wire supported in the casing and insulated therefrom at a level to be contacted when the piston under which it is positioned moves below the axis of rotation of the balance lever and above the lowermost limit of travel of said piston, the wire being sufficiently resilient to flex under the weight of the piston and not appreciably retard the movement of the piston.
 5. Apparatus as defined in claim 4 in which each wire is separately supported on a binding post passing through the casing but insulated therefrom, the binding post being adjustable to change the level of the wire with respect to said common lower limit of travel of the two pistons.
 6. Apparatus as defined in claim 4 in which each wire is separately supported on its individual binding post which passes horizontally through the casing and is rotatably adjustable about its axis, the wire being eccentrically mounted on the inner end of the binding post whereby its elevation with respect to the piston under which it is located may be adjusted by rotating the binding post. 